Fixing bones/armatures
There are several ways you can do it; a couple of them:


set a copy rotation constraint on the bone.002, targeting Bone and a copy rotation on the upper bone (local space, if something reotates in a weird direction check axis view in the armature propreties and set the appropriate bone roll to every bone in edit mode).





extrude a new bone from the upper bone and set it as target of an IK constraint of bone.002, lenght 1; set the upper bone to copy the rotation of "bone" as the previous example.